Obesity and sarcopenia in patients with rheumatoid arthritis: a cross-sectional study

Background. Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that leads to irreversible damage and deformation of the joints and is associated with an increased risk of death from cardiovascular disease. Metabolic disorders, manifested by changes in lipid and carbohydrate metabolism, and vascular manifestations of systemic inflammation contribute to the development of obesity in RA patients. Sarcopenia (SP) in RA is considered as another comorbid condition that develops against the background of a chronic inflammatory process, limitation of physical activity and the use of glucocorticoids, which can also worsen the prognosis of the disease. Objective: Evaluation of the frequency of pathological body composition phenotypes (obesity, SP, and sarcopenic obesity) in women with RA. Methods The study included 91 women aged 40-75 years with confirmed RA. All patients underwent clinical and laboratory examination and dual-energy X-ray absorptiometry to assess body composition. Results. Obesity was revealed in 72.5% of the examined individuals according to the results of absorptiometry, and only in 28.6% - by a body mass index of >30 kg m2. In 18.7% of patients, the body composition phenotype was without pathological changes, while 53.8% of RA women had obesity without SP, 8.8% - non-obese SP, and 18.7% - sarcopenic obesity. Women with sarcopenic obesity had a significantly longer duration of RA (p=0.02) and a higher disease activity score DAS 28 (p=0.04). Inverse correlations were established between fat and muscle mass and the of C-reactive protein level and cumulative dose of glucocorticoids, positive correlation - with the serum creatinine and uric acid levels and the mineral bone density of the spine and hip. Conclusion. Our study showed a high frequency of pathological body composition phenotypes in RA patients. Only 18.7% of the examined individuals had no abnormalities in the composition of the body, while 53.8% of the patients were obese, and another 18.7% had sarcopenic obesity. Densitometry for assessing body composition is advisable for identifying SP and more accurate diagnosis of obesity in order to conduct preventive measures both to prevent locomotor disorders and to reduce cardiovascular risk in RA patients.

rheumatoid arthritis, body composition, muscle mass, sarcopenia, sarcopenic obesity, body mass index, densitometry